A device and method for treating patients with movement disorder associated akinesia is described.
A movement disorder is a neurological disturbance of motor control that leads to abnormal movement. Movement disorders include Parkinson's disease (PD), Huntington's disease, atypical Parkinsonism such as progressive supranuclear palsy (PSP) and Multisystem atrophy (MSA), Wilson's disease, Tourette's syndrome and various chronic tremors. The secondary effects of stroke may also be included in this list even though stroke itself is not considered a movement disorder. Different clinically observed movement disorders can be traced to the same or similar areas of the brain.
Freezing of gait (FOG) is a common complication in movement disorders (e.g. 80% of PD patients), and leads to falls and injuries. Walking difficulties in these movement disorders may include shuffling, festination and akinetic episodes, which are popularly referred to as freezing. Akinesia means partial or complete loss of movement. Relative to Parkinsonism, akinesia usually denotes the sudden inability to initiate movement. Arms and hands may become momentarily akinetic, but much more commonly the feet/legs become akinetic or freezing. These freezing episodes present a distressing problem for the individual and impair their ability to walk normally.
PD is a chronic, progressive, neurodegenerative disorder resulting from the selective degeneration of specific brain cells of the substantia nigra. The incidence of PD is reported as 1% of the population over the age of 50, and as high as 10% over the age of 65. There are over 1.5 million persons with PD in the United States. Clinical presentation of the disease includes resting tremor, rigidity, bradykinesia or akinesia, and loss of postural reflexes.
FOG responds poorly to pharmacological and surgical treatment. FOG has been linked to diminished internally generated movement cues due to the damage to the basal ganglia. Externally provided auditory rhythmic cues have been shown to influence movement speed in patients with FOG. However, problems remain when patients tried to synchronize to the cueing frequencies and the training effects were not sustained once the cues were removed.
Everyday, PD patients with FOG are at risk of falls and injuries. It affects their quality of life and the lives of their loved ones. The falls and injuries can impact them financially. The risk of falls and injuries can increase the anxiety level in the patients and their families. Since FOG does not respond to pharmacological and surgical treatment and FOG can occur both during the “on” and “off” medication period, finding an effective, easy-to-use, low cost and reliable way to resolve the FOG becomes very urgent.
Usually, FOG is associated with the advanced stages of PD (stage 3, 4, or 5) but it can also be present earlier in the disease course when balance is still intact. Individuals have described their feet as suddenly being “stuck”, “glued” or “cemented” to the floor for brief (seconds) or longer (minutes) periods of time. This happens spontaneously while they are walking or as they begin walking (start-hesitation) with little warning. Some people are prone to FOG when they approach a narrow space, threshold or doorway. FOG may occur once or several times in succession during a short walk, and the incidence of episodes may vary from day to day. FOG and/or start-hesitation impedes free mobility and, as the disease progresses, increases the risk of falling.
People have attempted to manage FOG in various ways. The scientific basis for the management techniques usually involve providing some visual cue which encourages the feet to step up and over, as if unsticking from glue, rather than stepping forward, as with regular walking. These tricks are usually taught in the physician's office by the doctors, nurses and therapists who are familiar with the symptom. People also learn the methods from reading books about PD or by attending support group meetings. One technique that some use is to move to sound cues such as marching music or counting. Another method is to draw an imaginary line in front of the afflicted person's feet and encourage the patient to step up and over the imaginary line. Also used is the dropping or placing of objects (e.g. paper, tissue, straws, belts, etc.) on the floor in front of the person's feet; forcing them to step over the object.
The aforementioned interventions have been helpful to people, but each has drawbacks. Dropping or placing items of the floor requires not only that you have the objects ready to use but also that someone be available to place and retrieve the objects. One alternative to this is to use small disposable objects (e.g., cards) and leave the object(s) behind. With other objects, if the object is 3-dimensional, such as a belt, the individual could trip and fall. The imaginary line method works well, but again, someone usually must accompany the individual to draw the line with their foot or hand. Some patients find it difficult to imagine a line during the FOG episode and remain unable to move until involuntary release occurs. Sound cues (such as marching music) are not often feasible, particularly outside the home, and many find singing or counting aloud embarrassing. Often, a PD patient will just sit down and stop what he or she is doing. These tricks are some of the only mechanical techniques available to individuals in the United States who suffer from FOG and start-hesitation and they are often impractical for daily use.
More modern devices that have been developed to manage FOG include a projection device that projects a thin beam or discrete pattern of light using a laser, flash or other high-intensity light source to provide a luminous mark in the path of a standing individual (U.S. Pat. No. 5,575,294). This is a visual cue similar to the tricks described above and overcomes some of the problems inherent for such cues. It can be used alone or adapted to an assistive support such as a cane or walker, or to an item of clothing. It still requires the user to activate the device and does not automatically activate when FOG has been detected. If the user has akinesia in the arms and hands, the device is limited in its usefulness.
To overcome the user activated problem, Gesotti (U.S. Pat. No. 7,369,896) has developed movement timing stimulator systems and methods. The system including one or more motion sensors adapted to detect one or more movement parameters of a patient, a control panel, a plurality of customized parameter setting menu, and an over voltage/current monitoring circuit. The system further includes a controller that receives signals from the one or more motion sensors, control panel, customized parameter setting menus, and monitoring circuit and determines when stimulation prompts are required for a desired treatment of symptoms and a plurality of cutaneous stimulation electrodes placed in the vicinity of motor points for timed periodic stimulation prompts, wherein the stimulation prompts are sequentially applied based on the desired treatment of symptoms. The plurality of stimulation prompts is produced using multiple stimulation channels and each stimulation channel is associated with a cue clock. This system is complex, difficult for a user to place on the body and uses stimulation prompts that are electrical in nature. The system does not trick the user to move but “shocks” the user into movement, with the subsequent risks associated with such stimulation.
Thus, there is a need in the art for safe, reliable and simple methods to treat patients faced with FOG and improve outcomes. The methods should provide continuous use and should not be so complicated that caregivers will reject their use. Other objects, features and advantages of the present invention will become apparent from the following detailed description. It should be understood, however, that the detailed description and the specific example, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from the detailed description.